As one of the conventional electrical connecting apparatuses of this kind is proposed an electrical connecting apparatus comprising a probe board provided with a plurality of probes and enabling adjustment of the planarity of the probe board (refer to Patent Document 1). With this conventional electrical connecting apparatus, a thrusting force or a tensile force can act from a support member supporting the probe board toward a part of the probe board. Adjustment of this acting force can correct bent deformation of the probe board even if the probe board is bent to maintain the planarity of the probe board.
Accordingly, since the planarity of the probe board can be maintained by the aforementioned adjustment work after the probe board has been attached to the support member even if the probe board is bent and deformed at the time of manufacture of the probe board provided with the plurality of probes, the tips of the plurality of probes extending from the probe board can be held on the same plane. Thus, since the tips of all the probes can reliably contact electrical connecting terminals, corresponding to the respective probes, of an electrical circuit as a device under test, efficient electrical contact can be attained between them.
However, in the aforementioned prior art described in Patent Document 1, adjustment is needed every time of attachment of the probe board to the support member in accordance with bent deformation introduced in each probe board so that all the probe tips are located on the same plane. The adjustment work to make all the probe tips appropriately contact the aforementioned corresponding respective electrical connecting terminals of the device under test in a state where the probe board is attached to the support member is troublesome and requires skills. Especially, in a test of numerous integrated circuits formed on a semiconductor wafer, the number of probes of the probe assembly significantly increases, and thus the adjustment work to let such numerous probes appropriately contact the corresponding respective pads on the semiconductor wafer is not easy.
Under such circumstances, the present applicant proposed in a prior International Patent Application (PCT/JP2005/009812) an electrical connecting apparatus that requires no planarity adjustment work of the probe board after being attached to the support member regardless of the deformation of the probe board and enables reliable electrical connection between the probes and the corresponding electrical connecting terminals of the electrical circuit as a device under test.
In this electrical connecting apparatus, the probes are formed on the probe board that is bent and deformed in a free state under no load so that the tips are aligned on the same plane. Between the attachment surface of the support member and the probe board is arranged a spacer allowing an attachment bolt to pass therethrough, and the spacer acts to keep the aforementioned deformation of the probe board at the time of tightening of the attachment bolt. Accordingly, since the probe board is attached to the reference surface of the aforementioned support member in a state of keeping the aforementioned deformation, all the probe tips are located on the same plane.
Thus, after the probe board is attached to the support member, the tips of all the probes can be thrust to the respective electrical connecting terminals of the electrical circuit as a device under test approximately uniformly without the need for the conventional adjustment work for planarization of the probe board. As a result, the aforementioned conventional troublesome planarity adjustment work is not needed per replacement of the probe assembly, which enables an efficient electrical test.
However, the length dimension of the space of this kind includes a process tolerance, which is an allowable error at the time of manufacture of it. Also, the respective abutting parts of the support member and the probe board receiving the edge surfaces of the spacer also include respective process tolerances. Thus, even when the electrical connecting apparatus having the support member, spacer, and probe board manufactured within the respective process tolerances is assembled, variation exceeding a predetermined tolerance may occur in the height positions of the probe tips due to the synergistic effect of the process tolerances of the respective parts.
In order to restrict this variation, there is an idea of decreasing the respective process tolerances of the support member, the spacer whose one edge abuts on the attachment surface of the support member, and the probe board on which the other edge of the spacer abuts. However, heightening their process accuracies to decrease the process tolerances of the respective component parts raises their costs, as a result of which the price of the electrical connecting apparatus gets high.
[Patent Document 1] Japanese Patent Appln. Public Disclosure No. 2003-528459